D.C. United supporters show their colors during second half at sold-out Audi Field. (Katherine Frey/The Washington Post)

When he immigrated from Guatemala in 2002, Israel Lopez got a job in Washington and made himself a D.C. United fan. His note to self: Watch United on TV and attend matches, whether the club was sliding or surging. He’d refuse to let the players on the field dictate his fandom or enjoyment.

He doesn’t wear a United jersey with a player’s name on the back because he doesn’t want to root or show appreciation merely for one player. He wants to cheer the whole team. That won’t change, he said, even when star forward Wayne Rooney departs after this season.

“I say, no matter what, I will come here and enjoy myself,” Lopez said Sunday night, wearing a United cap and polo. “I am all about D.C.”

Rooney’s arrival last summer brought fans scurrying to buy individual, group and season tickets. His impending offseason departure for second-tier English club Derby County has them disappointed, many fans said Sunday during United’s 2-1 win over the Los Angeles Galaxy. But the No. 9 Rooney jerseys, in black and red, still dotted Audi Field: in lines for beer, in Section 117 and a few rows from the playing surface.

Some fans wearing Rooney’s jersey said they were there in part because of Rooney, no doubt. They acknowledged that he is the record goal scorer for England’s national team and for Manchester United and that his presence in D.C. has bolstered United’s attack and jolted United’s fan base to life. For those reasons, they generally are grateful Rooney arrived in Washington last summer, coinciding with the opening of Audi Field, and not bitter he’s on his way out.

“Him being here was a key factor for me being here,” said Matt Delano, who lives in Washington and bought season tickets for this year. “He’s a super nice guy. That definitely helped me become even more of a fan of his.”

Asked whether he’ll purchase season tickets again next year, when United won’t have Rooney, Delano said: “Oh, definitely. But we’ll definitely miss Rooney, too.”

The captain’s contract with United earned him a team-record $3.5 million in base salary this season, and it was supposed to run through the 2021 season before family concerns prompted an earlier departure. Rooney, who turns 34 in October, will remain with United for the final eight regular season matches and the playoffs, should United (10-7-9, 39 points) advance.

“Football is a game where opportunities come up,” Rooney said last week in an interview with The Washington Post, “and as a player you have to make those decisions, which aren’t always easy and won’t please everyone. I just hope everyone respects the decision and understands it is a step toward the next chapter in my career in football.”

United’s ticket sales are up nearly 400 percent since 2017, according to Andy Bush, United’s chief revenue officer. He attributed the bump to a number of factors, including Rooney’s arrival, the team’s postseason run late last season and the long-awaited opening of Audi Field.

He said there’s no concern internally that Rooney’s absence will prompt fans to stay at home rather than spend a night at the new stadium in Southwest Washington.

“Even when we haven’t played well, the excitement and energy still exists,” Bush said. “We have an environment and venue that works. … We knew [Rooney] wouldn’t be here for the next 10 years. He left sooner than anticipated, yeah, but he’s leaving for the right reason. You can’t question someone who’s leaving for family.

“So for us, it’s simple: Make Audi Field the best experience we can,” Bush continued. “That’s the environment. Wayne didn’t play [Sunday night], and the energy in the building was incredible. We had the biggest Sunday we’ve ever had.”

Indeed, Sunday’s crowd of 20,006 was United’s second sellout of the season; the other was for LAFC’s visit in April.

While munching on nachos and popcorn before the game Sunday, season ticket holders Heather and Rick Gaona said they do not believe Rooney leaving will have a profound effect on the team’s identity. Nor will it impact how they identify with the team, they said.

If anything, Heather said, she thinks Rooney’s departure will open the door for a younger prospect or two.

“He reinvigorated the team and the fan base,” she said. “This park is representative of the D.C. area, because it feels very inclusive and welcoming — even without Rooney.”

Then Rick chimed in. “It’s sad, the departure, but it won’t affect us,” he said. “One man doesn’t make a team.”

Steven Goff contributed to this report.

Read more United coverage from The Post:

Luciano Acosta’s benching, Zlatan Ibrahimovic’s record and other notes from D.C. United’s victory

Without Wayne Rooney, D.C. United defeats Zlatan Ibrahimovic and Los Angeles Galaxy, 2-1

D.C. United GM on the transfer window, Wayne Rooney, Mesut Özil and more